What is the mechanical world picture?

Early modern philosophy and science are often said to have put a “mechanical” or “mechanistic” conception of nature at the center of Western thought.  Robert Boyle referred to it as “the mechanical philosophy.”  Historian of science E. J. Dijksterhuis characterized it as a “mechanization of the world picture.”  Tim Crane calls it “the mechanical world picture.”  But what does a mechanical or mechanistic conception of the world amount to? 

Dijksterhuis’s book The Mechanization of the World Picture surveys the history of the period during which this conception rose to hegemony, and in the Epilogue he considers several possible interpretations that the survey suggests.  First, it is commonly said that a mechanistic conception of the natural world is one which sees it as a kind of machine, analogous to a clock.  And such metaphors are, he says, indeed frequent in writers of the period.

Leo XIV contra the new Babel: Reflections on the pope’s landmark encyclical

Last week, Pope Leo XIV issued Magnifica Humanitas, the first encyclical of his pontificate.  It has received much attention, both positive and negative and in both Catholic and secular media.  Much of the commentary so far strikes me as superficial.  To judge from social media, you’d think the document is primarily devoted to artificial intelligence, with some irrelevant comments about slavery and just war theory arbitrarily tacked on.  You’d also think those comments mark a rupture with traditional Catholic teaching.  None of this is true.  There is no break with traditional teaching.  While artificial intelligence (or AI) gets significant attention, the encyclical is actually devoted to a much larger theme, of which AI is only a part.  And the remarks on slavery and just war theory are not arbitrary, but fit in naturally with this larger theme.  Magnifica Humanitas is in fact a major contribution to the tradition of Catholic social teaching inaugurated by the pope’s namesake Leo XIII in Rerum Novarum.  It is rich in insights, and gives Catholics a sound framework for dealing with the “new things” of our times, just as Rerum Novarum did for Catholics of the late nineteenth century and beyond.

Nagel on Stroud on the possibility of metaphysics

Much of modern philosophy has been hypnotized by the idea that causality, necessity, and value are not features of objective reality but merely features the human mind projects onto reality.  David Hume is, of course, the main hypnotist in this connection.  In his important book Engagement and Metaphysical Dissatisfaction, Barry Stroud holds that the arguments for this skeptical attitude do not succeed, and that causality, necessity, and value in fact cannot coherently be eliminated from our conception of the objective world.  At the same time, he does not think that this yields a proof that they really are features of the objective world.  It may be that they are illusions after all, even if we can’t help but believe in them.  Hence, if metaphysics is concerned with establishing one way or another whether such features really are part of objective reality, it is, in Stroud’s view, an impossible project.

No, the U.S. has not been at war with Iran for 47 years

After the United States and Israel attacked Iran at the end of February of this year, the war’s defenders suddenly began to claim (and incessantly to repeat) that the U.S. has already been at war with Iran for 47 years.  Evidently, the motivation for this newly minted talking point is to try to defuse two obvious objections to the war: that it is a war of aggression and therefore unjust, and that it did not receive constitutionally required congressional authorization and is therefore illegal.  The idea is that, if the current operation is part of a wider war that is already longstanding, then it does not constitute aggression and does not need special authorization.

The transmission theory of authority

Scholastic thinkers like Cardinal Cajetan, St. Robert Bellarmine, and Francisco Suárez developed what is sometimes called a “transmission theory” of governmental authority.  It holds that such authority ultimately comes from God, but is directly vested by him in the community as a whole, and then transmitted by it to some particular form of government (which may or may not be democratic).  Yves Simon offered an influential discussion of this theory in chapter 3 of his book Philosophy of Democratic Government.

Misunderstanding the “just cause” condition of just war doctrine

In a recent article at First Things, I argued that the just war tradition holds that for a war to be justifiable, it must be morally certain that it meets just war conditions (not merely arguable or even probable that it meets them).  Some readers have objected that some of the sources I cited require moral certainty only with respect to the “just cause” condition, not the other conditions.  If so, then it might seem that we can (contrary to what I claimed in the article) be morally certain that the Iran war meets the “just cause” condition.  For war aims like liberating the Iranian people or preventing an oppressive government from acquiring nuclear weapons are (so the argument goes) surely manifestly just.

Just war doctrine and moral certainty

In an article at First Things, I show that the standard view in the Catholic just war tradition is that for a war to be just, it is not enough that it be merely arguable or even probable that it meets all just war criteria. We must be morally certain that it meets them.

The Journal of Natural Law

The first issue of The Journal of Natural Law has now been published.  Among other things, it includes my review of Stephen Boulter’s book Natural Law Liberalism and the Malaise of Modernity.

Caught in the web

At The Telegraph, John Haldane remembers the late Dominican theologian Fr. Fergus Kerr.

At UnHerd, Sohrab Ahmari has had enough with Donald Trump’s “mad king” governing style, and sides with Pope Leo in his feud with the president.

James Franklin’s new book The Necessities Underlying Reality: Connecting Philosophy of Mathematics, Ethics and Probability is available by Open Access.

American Songwriter reports that Donald Fagen has retired from touring with Steely Dan.  More details at Vulture.

The New Neo-Scholasticism

My article “The New Neo-Scholasticism” appears in the Winter 2026 issue of the American Catholic Philosophical Quarterly.  It is available for free download here.  Here is the abstract: “The last quarter of a century has seen the rise of what can aptly be labeled a new Neo-Scholastic trend in philosophy and theology. After explaining what Scholasticism and Neo-Scholasticism are, the article describes the origins, themes, and key thinkers of this latest iteration of Scholasticism that is taking up the mantle of the old.”

Rational social animals and addiction

Roger Scruton’s book Beauty contains an interesting brief treatment of addiction.  Too much discussion of this topic today overemphasizes neurochemistry.  That is by no means to deny that that aspect of the issue is real and important.  But it addresses only what Aristotelians would call the material and efficient causes of habituation, and not the formal and final causes.  The latter concern our nature as rational social animals, and as Scruton’s discussion indicates, addiction involves disorders related to both the social and rational aspects of that nature.

Of the connection between addiction and pleasure, Scruton writes:

Addiction arises when the subject has full control over a pleasure and can produce it at will.  It is primarily a matter of sensory pleasure, and involves a kind of short-circuiting of the pleasure network.  Addiction is characterized by loss of the emotional dynamic that would otherwise govern an outward-directed, cognitively creative life.  Sex addiction is no different in this respect from drug addiction; and it wars against true sexual interest – interest in the other, the individual object of desire.  Why go to all the trouble of mutual recognition and shared arousal, when this short cut is available to the same sensory goal? (p. 186)

Will “a whole civilization die tonight”?

From Twitter/X, on the president’s deranged post of this morning (which managed to top even his deranged Easter post):

Contra White and Graham

From Twitter/X, on the comments made at the White House yesterday by Paula White and Franklin Graham:

Texts on tyranny from the tradition

“These will be the ways of the king who will reign over you: he will take your sons and appoint them to his chariots and to be his horsemen, and to run before his chariots…and to make his implements of war…He will take the best of your fields and vineyards and olive orchards and give them to his servants. He will take the tenth of your grain and of your vineyards and give it to his officers and to his servants…He will take the tenth of your flocks, and you shall be his slaves. And in that day you will cry out because of your king, whom you have chosen for yourselves; but the Lord will not answer you in that day” (1 Samuel 8:11-18)

The epistemology of microphysics

On March 21, I delivered a lecture on “The Epistemology of Microphysics” at the 49^th Annual Meeting of the American Maritain Association at Loyola Marymount University.  You can read the lecture here.  The AMA also kindly presented me with its Scholarly Excellence Award for 2026.  Many thanks to the AMA and all who participated.

Just war doctrine and the duties of soldiers

The main point of just war doctrine is to guide public authorities in determining whether a military action they are considering is morally defensible.  In a democratic society, it also assists citizens in carrying out their own duties as voters, opinion makers, and so on.  But what of the servicemen who have to fight in the wars their governments decide to wage?  Do they have an obligation to make a moral judgement about these wars in light of just war criteria?  Must they refuse to fight in an unjust war?

Naturally, the just war tradition has addressed these questions.  What follows is an explanation of the basic principles.  The first thing to say is that the tradition draws a distinction between two main sets of questions: jus ad bellum questions, which have to do with the conditions under which a war may justly be entered into; and jus in bello questions, which have to do with how a war is to be conducted once it has started.

Harrington on “Thomophobia”

Earlier this month, British author Mary Harrington delivered a First Things Lecture titled “Our Crisis is Metaphysical” in Washington, D.C.  You can now watch the lecture at YouTube.  Just past the eleven minute mark, Harrington makes some very kind remarks about my book Scholastic Metaphysics, about which she says: “I don’t think Professor Feser intended it as a page turner, but I tore through it like it was an airport novel.”  As she explains in her lucid and important talk, she finds in Aristotelian-Thomistic metaphysics the vocabulary needed properly to understand today’s deepest moral and political controversies.  Especially important, as she says, are the distinctions between (a) act and potency, (b) substance, accident, and substantial form, and (c) the four causes.  She notes that it was the moderns’ attack on and burial of Aristotle, Aquinas, and Scholasticism that would pave the way for developments such as feminism, contraception, and the trans phenomenon.  And she says that these are held in place by a “Thomophobia” (great coinage!) that dismisses traditional metaphysics a priori as a tool of oppression.  Give her lecture a listen.

Thomism Revisited

Thomism Revisited, a new anthology edited by Gaven Kerr, is out this month from Cambridge University Press.  It includes my essay “The Thomistic Critique of Neo-Classical Theism.”  (I have defended Thomism from neo-classical objections in earlier work. This new essay goes on offense.)  The table of contents and further information about the volume are available here.

America’s conflict in Iran is not a just war

In a new article at Public Discourse, I argue that it is even more obvious now than it was at the start that the Iran war does not meet the conditions for a just war.

Dissent and double standards at Where Peter Is

Mike Lewis, editor of Where Peter Is, is well known for freely accusing fellow Catholics of “dissent” from the teaching of the Church.  Yet he recently published an article at the website dissenting from the Church’s declaration that its teaching that the sacrament of Holy Orders is reserved to men is “infallible” and that assent to it must be “irrevocable.” I discuss this development in an article at The Catholic Herald.

The New Neo-Scholasticism

For those with access to the American Catholic Philosophical Quarterly, my forthcoming article “The New Neo-Scholasticism” is available in an online first version.

The U.S. war on Iran is manifestly unjust

Last summer the United States joined in Israel’s attack on Iran’s nuclear program.  Many of us warned that it would be difficult for the U.S. to participate without being drawn into an open-ended conflict.  The Trump administration and its defenders claimed vindication when the operation ended swiftly, a purported “one and done” mission that had painlessly accomplished what it set out to do.  “Iran’s nuclear facilities have been obliterated,” said the White House, “and suggestions otherwise are fake news.”  Fast forward just eight months and an administration official was issuing the dire warning that Iran was “probably a week away from having industrial-grade bombmaking material” – deploying thirty-year-old rhetorical shtick so hackneyed that it is a marvel anyone still believes it.  Now we are at war with Iran, the cocky “one and done” chatter suddenly thrust down the memory hole.

Xenophanes and natural theology

Natural theology is knowledge of the existence and nature of God that can be attained through the use of our natural rational powers, specifically through philosophical arguments.  Like many other themes in philosophy, it goes back to the very beginnings of the enterprise, in the work of the Pre-Socratics.  In another post I suggested that Anaximander, specifically, could arguably be seen as its founder.  The usual and certainly defensible view, though, is that that honor goes to Xenophanes.  In God and Greek Philosophy, Lloyd Gerson writes:

In Xenophanes we can discover the first clear instance of the Ionian speculative approach applied to natural theology.  That for which there is little evidence in Anaximander is more explicitly stated in Xenophanes… Accordingly, it seems appropriate to call Xenophanes the first natural theologian.  By this I mean that he is the first to attack the theology of the poets and to offer as a substitute a form of theology based upon argument. (p. 17)

Cancelled in L.A. (Updated)

I had been invited to speak later this month at St. John’s Seminary in Los Angeles. I have now been informed that the event is being cancelled, due to complaints from unnamed critics who find me too controversial. Meanwhile, the always controversial Fr. James Martin will be speaking this month at the Los Angeles Religious Education Congress, on the theme “Hope on the Horizon: LGBTQ Catholic Update 2026.” It appears that, for some in Archbishop Gomez‘s archdiocese, Fr. Martin is welcome to speak about that topic to educators of Catholic youth, but I am not welcome to speak to seminarians about how to defend the Church’s teaching on the soul’s immortality.

UPDATE 2/19: An update on what happened, to counter various unwarranted speculations I’ve seen here and elsewhere. My understanding from official sources is that my social media activity was judged to be controversial, and in particular that the archbishop had received complaints from some who had concerns about my having been critical of Pope Francis. No specific views or remarks of mine were cited. My understanding from other credible sources is that the complaints came, specifically, from a number of older priests in the L.A. area who had seen an announcement about the talk that had been sent to parishes. (This makes sense given that the talk was cancelled very soon after it was announced – within a day or so – and the print and online announcements were highly unlikely to have been seen before that time by many except people with some connection to or special interest in the seminary.)  That is all I am able to say at this time.

No, AI does not have human-level intelligence

In an article at Nature, Eddy Keming Chen, Mikhail Belkin, Leon Bergen, and David Danks ask “Does AI already have human-level intelligence?” and claim that “the evidence is clear” that the answer is Yes.  (Though the article is partially pay-walled, a read-only PDF is available here.)  But as is typical with bold claims about AI, their arguments are underwhelming, riddled with begged questions and other fallacies.

Defining “intelligence”

Naturally, before we can establish that AI has genuine intelligence, we need to make clear what it would be for it to have intelligence, and how we could go about determining that it has it.  The first is a metaphysical question, the second an epistemological question.  Our authors make no serious attempt to answer either one.

Van Fraassen on microscopy

Philosopher of science Bas van Fraassen is well known for defending the “constructive empiricist” position that the success of a scientific theory does not compel us to believe in the existence of the theoretical entities it posits.  In his view, a scientific theory aims only to be empirically adequate, in the sense of correctly describing the world of observable things.  When a theory is successful insofar as it makes accurate predictions or opens the door to technological advances, this gives us reason to believe only that it is empirically adequate, not that it tells us anything about a realm beyond what is observable.

Scientific realists take the contrary view that the success of a theory does give us reason to believe in the theoretical entities it posits.  Among other arguments, they sometimes appeal to the idea that entities that at one time were unobservable later became observable with the rise of new technologies, such as telescopes, electron microscopes, and ordinary microscopes.  This shows, they argue, that the boundary between observable and unobservable entities is not sharp enough to justify skepticism about the latter.

Socratic politics: Lessons from the Gorgias

Almost forty years ago, the liberal pragmatist philosopher Richard Rorty published an essay titled “The Priority of Democracy to Philosophy.”  I recall hating it immediately, from the title alone.  The sentiment was appalling coming from anyone, but especially from a philosopher.  Philosophy aims at the true and the good, democracy merely at what the majority happens to want.  That can sometimes be false and very bad indeed – and in one notorious case it was the execution of Socrates, the model for all philosophers.  How could philosophy not have the priority?

Prioritizing democracy

But what exactly is it for either to have “priority” to the other?  What Rorty had in mind is this.  The liberal democratic tradition has pushed religion ever further out of the public square.  Theology is now widely regarded as a purely private interest whose claims have no bearing on the political order.  But for centuries, liberalism took philosophy to retain political relevance.  In particular, liberal theorists took their favored polity to require philosophical foundations – in Locke’s natural rights theory, Mill’s utilitarianism, or whatever.

Church history does not support Trump’s expansionism

Some Catholic voices online have been suggesting that the example of Spanish colonialism justifies the Trump administration’s expansionist foreign policy – including the threat to take Greenland by force.  Catholic podcaster Matt Walsh, with whom I recently had a lively exchange about these matters on Twitter/X, appeals to Catholic colonialism and also claims that a war to secure resources is "totally legitimate."  Others appeal to the Crusades, or to ancient Israel’s conquest of Canaan.  In a new article at First Things, I argue that all of these arguments are fallacious.  They ignore crucial moral and theological differences between the cases.  Church history provides no support for Trump’s jingoistic expansionism.

Pope Leo XIV on politics and the death penalty

From a couple of posts today at Twitter/X, commenting on Pope Leo’s address to the diplomatic corps at the Vatican:

A marvelous address by @Pontifex that condemns the pathologies of both the woke left and the jingoist right. Against the left, he denounces “the so-called ‘right to safe abortion,’” warns of “a subtle form of religious discrimination against Christians” by which they are “restricted in their ability to proclaim the truths of the Gospel for political or ideological reasons,” and decries “a new Orwellian-style language…which, in an attempt to be increasingly inclusive, ends up excluding those who do not conform to the ideologies that are fueling it.” Against the right, he warns of “excessive nationalism," affirms "the importance of international humanitarian law," and notes that “a diplomacy that promotes dialogue and seeks consensus among all parties is being replaced by a diplomacy based on force… peace is sought through weapons as a condition for asserting one’s own dominion." And he decries the fact that on every side of our political culture and social media, “language is becoming more and more a weapon with which to deceive, or to strike and offend opponents” rather than used “to express distinct and clear realities unequivocally.”

(From Twitter/X)

Review of Gorman

Readers who have access to the journal The Thomist might be interested in my review of Michael Gorman’s terrific book A Contemporary Introduction to Thomistic Metaphysics, which appears in the January 2026 issue.

Interview on the Venezuela situation

In an interview with Edward Pentin published at his Substack, I discuss just war doctrine, the Venezuela situation, and the false choice between globalism and jingoism.

On Searle at First Things

On the Editor’s Desk podcast at First Things, Rusty Reno and I discuss John Searle and his place in contemporary philosophy. (The take-off point of our discussion is my recent article on Searle in the magazine.)

Some basic principles of masculinity

From Twitter/X today, inspired by an excellent article by Justin Lee:

Catholic natural law thinkers on nation versus race

As I’ve noted many times (e.g. here and here), natural law theory and Catholic moral theology both affirm the indispensable role in human life of the nation, which is a natural social formation.  The nation is an extension of the family, and like family members, citizens of a nation are typically related by common ancestry.  However, in neither case is this strictly necessary.  Just as someone might become part of a family by marriage or adoption, so too might someone become part of a nation through immigration and assimilation.  Moreover, nations are much looser social formations than families, and common descent is much less essential to them than it is to the family.

Merry Christmas

Merry Christmas to all my readers. I love you all (including the grinches out there). May God bless you and yours!

Return of the missing links

My Christmas gift to you, dear readers – a revival of the blog’s “links of interest” posts, by popular demand.  Let’s get to it:

J.P. Andrew interviews Rob Koons and Daniel Bonevac about their two forthcoming books on Aquinas’s Five Ways.

At The New Yorker, Rachel Aviv reveals that neurologist Oliver Sacks made up many of the details of his famous case studies.

Sohrab Ahmari on the late Norman Podhoretz, at UnHerd.

At Fusion, Oliver Traldi on John Searle’s forgotten book The Campus War.

Jacob Savage on the lost generation that DEI created, at Compact.

Lawful authority in just war doctrine

In an earlier article, I set out the conditions that traditional just war doctrine says a war must meet in order to be morally legitimate, and argued that a war with Venezuela would not meet them.  Here I want to look more closely at one of those conditions, namely that a war can be just only if carried out by lawful authority.  It seems to me that many of those defending a prospective war with Venezuela too glibly assume that this condition has been met, and focus almost exclusively on what they take to be the justice of the cause.  I don’t think the justice of the cause has in fact been established, and indeed it has only become more doubtful in the week since my first article appeared.  But even if it had been established, that is by no means the only crucial consideration.

Kant’s claustrophobic metaphysics (Updated)

My review of Marcus Willaschek’s Kant: A Revolution in Thinking appears in the latest issue of the Claremont Review of Books.

UPDATE 12/20: The review is no longer behind a paywall.

Would a U.S. war against Venezuela be just?

To all appearances, the United States is preparing for war with Venezuela.  For months now, American military forces have been blowing up Venezuelan boats said to be carrying drugs.  The U.S. has deployed a fleet of warships off the country’s coast.  President Trump has said that “this is war” and that “very soon we’re going to start doing it on land too,” and he has ordered the closure of airspace over Venezuela.  He has also declared that Nicolas Maduro’s “days are numbered” as president of Venezuela and ordered him to resign and leave the country.  And it has been reported that the administration is planning for a post-Maduro Venezuela.

It's an open thread!

We’re due for an open thread.  Now is your chance to bring up matters that would otherwise be off-topic.  For example, sometimes readers want to respond to something I said on Twitter/X (and write up such a comment under a post here – where it doesn’t get past moderation if it’s not on topic).  But feel free to bring up whatever you like.  From Cantor’s continuum problem to Canter’s Deli, from Gertrude Stein to grapefruit wine, from Jack Kirby to Kier Kirby, everything is fair game for discussion.  Just keep it civil and classy, as always.  Previous open threads archived here.